AWS API Gateway - Getting Started

mbalsam · July 29, 2018, 9:50pm

Im trying to understand how to take our existing servicestack application and make it work with the AWS API Gateway…

I understand that the API gateway support Swagger and OpenAPI and so does servicestack.

With my very nieve understanding, I’m GUESSING that if I use service stack to generate an swagger file

http://localhost/app/openapi/

Save it and import it into the AWS API gateway, this might be the starting point to configure API Gateway?

When i do so i get this error.

Your API was not imported due to errors in the Swagger file.
Unable to create model for ‘xxxxx’: Invalid model specified: Validation Result: warnings : , errors : [Invalid model schema specified]

I’m not really sure if what I’m trying is possible or needed.

I know I could simply expose the IP of our self-hosted app that’s running in a container and be done with it, but then i would not have capabilities provided by the API gateway such as DDOS management and AWS IAM permission management.

mbalsam · July 29, 2018, 10:11pm

I also see that the AWS API sample swagger source, starts with

“swagger”: “2.0”,

Which maps to the SS Openapi package and not the SS swagger package.

mythz · July 29, 2018, 11:48pm

I don’t know if it’s possible to import it into AWS API Gateway, but the path to the Open API endpoint is /openapi.

But I couldn’t tell you what the cause of the error is, you could try to cut down the JSON to see if it can import a single service.

mbalsam · July 30, 2018, 5:07pm

Do many/any of other servicestack users who host on Amazon use the api gateway?

mythz · July 30, 2018, 7:54pm

We only get notified when people are having issues, not when something is getting used. The only issue I can recall that used AWS API Gateway was an AWS Lambda .NET Core issue:

github.com/ServiceStack/Issues

Issue with Serverless / Api Gateway / ServiceStack combination request deserialization

opened 11:14PM - 15 Feb 18 UTC

closed 01:59AM - 18 Feb 18 UTC

ryanhelms

Hey mythz, First, I have to say that this combination is very powerful when i…t works properly. We are able to have infinitely scalable, high-functioning ServiceStack endpoint that are just as feature rich as any other ServiceStack endpoint deployed in a container / EC2 environment. We have endpoints interfacing with Virtual File Systems, MQ pub/sub, etc but oddly enough, we break down when it comes to executing a POST / PUT to an endpoint and expecting to get a deserialized request object. The object basically comes through as a new object of the request type (empty - `Payload` property in the example below) with any properties that I explicitly define in the return coming back as expected (`Ping` and `UpTime` properties in the example below). I have setup a demo solution [here](https://github.com/ryanhelms/servicestack-serverless-apigateway) for you to have a look at. **Note**: I have an example api deployed using the steps below. You can use this one if you'd like but I was verbose here in case you wanted to reproduce it yourself from the ground up. Example endpoint deployed from steps below: - https://a0pxyby83h.execute-api.us-east-2.amazonaws.com/demo/ping =================================================================== The steps to reproduce the problem are: 1. Clone the [repo](https://github.com/ryanhelms/servicestack-serverless-apigateway) 2. Open your command prompt 3. `cd` to MyApp directory 4. `npm install` 5. Edit MyApp -> serverless.yml - change to an existing role with appropriate lambda deployment permissions [here](https://github.com/ryanhelms/servicestack-serverless-apigateway/blob/master/MyApp/serverless.yml#L11) - change to a temporary bucket to put serverless deployments in [here](https://github.com/ryanhelms/servicestack-serverless-apigateway/blob/master/MyApp/serverless.yml#L14) 6. From your command prompt, execute: `sls deploy --stage demo --region us-east-2` 7. After a successful deployment, get the endpoint url that was assigned for your service: example: https://a0pxyby83h.execute-api.us-east-2.amazonaws.com/demo/ping 8. Next, execute a GET request: - You should get back a response similar to: > { > "ping": "Get: Pong", > "upTime": "Service has been up for -XX:XX:XX.XXXXXXXX" > }` 9. Next, execute a POST request with: - the `Accept` header set to `application/json` - the `Content-Type` header set to `application/x-www-form-urlencoded` - the request property `Payload` set to `payload data` - You should get back a response similar to: > { > "payload": "payload data", > "ping": "Post: Pong", > "upTime": "Service has been up for -XX:XX:XX.XXXXXXXX" > }` 10. Next, execute a POST request with: - the `Accept` header set to `application/json` - the `Content-Type` header set to `application/json` - the request property `Payload` set to `payload data` - You should get back a response similar to: > { > "ping": "Post: Pong", > "upTime": "Service has been up for -XX:XX:XX.XXXXXXXX" > }` Obviously, this is where the problem is. I expect to get back `payload: "payload data"` here just as I did for the previous post. Any ideas are welcome. I'd love to get this working 100% as it has huge potential. Cheers!

Although they didn’t use Open API, they used Serverless to manage their AWS lambda functions and listed their API endpoints in their serverless.yml.

mbalsam · July 30, 2018, 8:17pm

FYI, was talking with amazon consultants today. They reviewed the file generated by the call to /openapi. Apparently, the AWS API Gateway openapi/swagger implementation has several known deficiencies.

https://docs.aws.amazon.com/apigateway/latest/developerguide/api-gateway-known-issues.html

From a quick scan, there are a few swagger primitives that servicestack uses that are not supported are:

The additionalProperties field is not supported in Models.
Numbers of the Int32 or Int64 type is not supported.

They said it would still be possible to use the API gateway by using their GUI to add individual calls for each path we want to support. In our case that would be too much for the value, it would provide.

Instead, they pointed me to use an Application Level Load Balancer in EC2 to proxy access to the rest calls.

We’re testing that now.